System for measuring the twist of spun yarn in open-end spinning

ABSTRACT

An open end spinning unit having feed means for delivering fibrous material, a rotary twisting means for spinning the fibers into a yarn, and a rotary withdrawing means for taking up the yarn. A first detector is located to sense the revolution of said twist means and providing an output having a value proportional to the number of revolutions. A second detector is located to sense the revolution of the withdrawing means and providing an output having a value proportional to the number of revolutions thereof. The first detector is connected to the output of a first counter between which is interposed a gate means. The second detector means is connected to the input of a second counter, the output of which is connected to the input of the gate, and which provides a signal for controlling the gate. An indicator is connected to the first counter to record the value received by the counter.

[ Apr. 22, 1975 SYSTEM FOR MEASURING THE TWIST OF SPUN YARN IN OPEN-ENDSPINNING [75] Inventors: Pavel Seidl; Milos Mladek, both of Usti nadOrlici. Czechoslovakia [73] Assignee: Elitex Zavody textilnihostrojirenstvi, generalni reditelstvi, Liberec, Czechoslovakia [22]Filed: Sept. 17, 1973 211 Appl. No.: 397,741

[30] Foreign Application Priority Data Sept. 15. 1972 Czechoslovakia6323-72 [52] U.S. C1 57/34 R; 57.89 [51] Int. Cl. D0lh 13/32; DOlh 1/12[58] Field ofSearch 57/58.8958.95.

[56] References Cited UNITED STATES PATENTS 2.982.083 5/1961 Brcitcnbach57/97 3.660.972 5/1972 Neill et a1. 57/34 R 3.678.673 7/1972 Prochazkaet a1. 57/58.95 3.680.299 8/1972 Lee. Jr. 57/34 R 3.704.579 12/1972Tooka et a1 57/34 R 3.791.128 2/1974 Landwehrkamp et a1. 57/93 3.803.8234/1974 Niestron et a1. 57/34 R Primary E.\'anziner.lohn PetrakesAttorney. Agent. or F irmMurray Schaffer [57] ABSTRACT An open endspinning unit having feed means for delivering fibrous material. arotary twisting means for spinning the fibers into a yarn. and a rotarywithdrawing means for taking up the yarn. A first detector is located tosense the revolution of said twist means and providing an output havinga value proportional to the number of revolutions. A second detector islocated to sense the revolution of the withdrawing means and providingan output having a value proportional to the number of revolutionsthereof. The first detector is connected to the output of a firstcounter between which is interposed a gate means. The second detectormeans is connected to the input of a second counter. the output of whichis connected to the input of the gate. and which provides a signal forcontrolling the gate. An indicator is connected to the first counter torecord the value received by the counter.

4 Claims, 2 Drawing Figures RELATED CASES The present invention anddisclosure is related to corresponding applications. Ser. No. 397.742and Ser. No. 397.743, filed on even date hereith. Reference andincorporation of the subject matter disclosed therein is made as if morefully set forth herein.

BACKGROUND OF INVENTION The present invention relates to a system formeasuring and indicating the twist number of spun yarn and in particularto a system for automatically measuring and detecting the twist impartedto the spun yarn in an open end spinning machine.

It has been known to determine the number of twists imparted to a spunyarn per unit length by separately measuring the number of revolutionsmade by the twist imparting member (i.e. the spinning turbine) andseparately measuring the withdrawing speed of the spun yarn from theturbine. After these individual measurements have been made a furthercomputation is manually obtained by dividing the data so as to obtainthe theoretical number of twists per unit length. This system ofdetermining the twist number is disadvantageous namely in that itrequires two considerably different measurements to be individuallytaken. Each of these measurements requires the use of special andprecise apparatus so that the computation which is later to be made maybe as accurate as possible. Furthermore, the determination of the twistnumber of the yarn so spun is not a direct computation and as aconsequence the resultant determination may not be accurate because of anumber of factors not related to the actual spinning operation.

It has been known to measure the twist number of spun yarn by untwistinga given or predetermined length of the yarn sample. By untwisting such asample it is possible to determine the actual number of twists in thegiven sample with respect to the drop in tension between the twisted anduntwisted yarn. The measurement of the twist number of yarn in thismanner re- I quires an interruption of the spinning process in orderthat the predetermined sample length may be taken. Thus this system isnot suitable for an instantaneous determination of the twist number ofthe yarn as it is being manufactured and during the actual spinningprocess. Furthermore. due to the character of the yarn structure anaccurate result cannot be expected since many errors can arise duringthe untwisting of the given length of yarn and during the actualmeasurement of the tension drop.

It is the object of the present invention to provide a system for theautomatic measurement and indication of the twist number of spun yarndirectly from the spinning unit during the spinning operation.

It is a further object of the present invention to provide a simple andreliable apparatus and system enabling the measurement and indication ofthe twist number during the spinning operation without requiring anyadditional or manual calculation.

It is a further object of the present invention to provide a system formeasuring and indicating the twist number of the yarn without the needto interrupt the spinning operation or to shut down the spinningmachine.

LII

The foregoing objects, other objects and numerous advantageous will beseen from the following disclosure of the present invention.

SUMMARY OF THE INVENTION According to the present invention there isprovided a system for measuring and indicating the twist factor or twistnumber of the yarn spun in an open end spinning unit. Open endspindleles spinning machines comprise a plurality of units each havingfeed means for delivering fibrous material. a rotary twisting means forspinning the fibers into a yarn and a rotary withdrawing means fortaking up the yarn. In accord with the present invention there islocated a first detector means by which the revolution of the twistmeans is sensed and which provides an output having a value proportionalto the number of its revolutions. A second detector means is locatedsensing the revolution of the withdrawing means and providing also anoutput having a value proportional to the number of its revolutions. Thetwo sensed values are evaluated in a circuit to which the input from thefirst detector is connected to a first counter. A gate means isinterposed between the first detector and the first counter. The seconddetecting means has its value output connected to the input of a secondcounter, the output of which is itself connected to the input of thegate. The second counter is so regulated that it provides a signaloperating the gate after a predetermined input value is fed to it. Uponthe passage of the signal to the gate. the first counter is blocked fromfurther input and is caused to transmit its received cumulative input toa digital or analog indicator.

Preferably. the second counter is provided with a decade number switchby which its input value may be decimally modified so that its input maybe provided over a broad range. Further, it is preferable that the detectors be contactless and comprise preferably. photoelectric cells whichare adapted to sense optical indicia or markings placed on the twistmeans or spinning turbine and the rotary withdrawing means withoutinterference with their operation.

Further details of the present invention are described in the followingspecification and are shown in the form of its exemplary embodiment inthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view of a spinning machine showing theapplication of the present invention to at least one of the spinningunits therein,

FIG. 2 is a circuit diagram of the evaluation unit employed and providedby the present invention.

DESCRIPTION OF INVENTION A more or less conventional spinning machine,of which there are many commercial embodiments available is depicted inFIG. 1. The machine comprises a frame 1 on which are aligned a pluralityof spinning units, each comprising a rotary turbine 2 mounted to rotateabout a horizontal axis 3. A silver 4 of fibrous material is withdrawnfrom a container 5 and passes through a dissolving and feeding mechanism7 to be fed to the chamber of the spinning turbine 2 where under theeffect of centrifugal action and suction it is spun into a yarn 7. Theyarn 7 is withdrawn between a rotary take up beam 8 and a hold down arm8a over a winding beam 9 to be wound on a bobbin 10.

In accordance with the present invention at least one of the spinningunits has its twist imparting turbine 2 provided with a detector 11adapted to sense its rotation. The detector 11 is mounted on the frameof the machine in opposition to the peripheral surface of the spinningturbine 2. which surface is provided with at least one marking indicia12. The detector 11 and the markings 12 are arranged in such a mannerthat the output of the detector provides a series of pulse signalshaving a value proportional to the number of revolutions of the turbine2. If one marking 12 is used the number in that case represents thenumber of passages of the marking 12 through the plane of the detector.Preferably, the optical marks 12 are formed on the point of thecircumference of the turbine 2 so that light is reflected from thesurface in a different manner than the remaining portions of theturbine. Preferably. the marking may be black. The detector ispreferably a photoelectric cell sensing the change in light reflectionor transmission and having electrical electronic means for producing aseries of output pulses in response thereto.

The rotary withdrawing beam 8 is also provided with a detector 13mounted in opposition to its circumferential surface on which is securedtape 14 itself provided with series of spaced optical markings 15. Thedetector 13 is similar to the detector 11 as are the optical markings 15to the markings 12 on the turbine 2. Thus the detector 13 is capable ofdetermining the rotation of the withdrawing beam 8 and produce an outputsignal comprising a series of pulses, the value of which beingproportional to the number of revolutions of the withdrawing beam 8. Inthis instance the number of black marking optical indicia 15 are suchthat the number of passages they make through the plane of the detectorduring a single revolution is proportional thereto.

The outputs of the detectors l2 and 13 are fed into an evaluation andcomparison circuit shown in FIG. 2. This circuit comprises a pair ofdetector inputs D and D which are adapted to be connected to thedetectors 12 and 13 respectively. The detector input D. is connected toa gating means 16 which has its output connected to a first counter 17which is adapted to transmit upon appropriate signal its accumulatedvalue to a digitronic indicator 18 by which the accumulated value may beread out either in digital or analog form. The detector input D isconnected to the input of a decade number switch 19, the outputs ofwhich is connected to a second counter 20, the output of which itself isconnected to the gating means 16. In general, the gate 16 is adapted tobe normally open allowing passage of the input from the detector input Dinto the first counter 17 and is closed upon the reaching in the secondcounter of a predetermined value from the input of the detector input DIn order to determine the twist number of the following relationship maybe employed:

wherein: z is the twist number,

0 is the number of revolutions of the twist imparting element or turbine2 during the withdrawal of a given length of yarn. and

L is the given length of yarn withdrawn over the withdrawing beam 8.

Preferably. one optical marking 12 is made about the circumference ofthe turbine 2 and the number of markings 15 made on the tape 14 securedto the withdrawing beam 8 is chosen in such a manner that the detector13 arranged in opposition to it has a value proportional to the numberof revolutions of the withdrawing beam which is I00 pulses after thewithdrawing of one meter of spun yarn. In this case the detector 13 isconnected by the decade number switch to the last two decades of thesecond counter 20. Thus the counter 17 and 20 begin tocountsimultaneously the pulses from each of the respective detectors 11and 13. And these pulses are continually accumulated in the respectivecounters. The initiation of the evaluation operation can be controlledby suitable control means regulating the operation of the gating means16 either manually or automatically. Such a control unit is shown in theaforementioned co-pending applications. After initiation. the countersl7 and 20 accumulate the pulses delivered through the detectors. Afterpulses from the detector l3 sensing the rotation of the withdrawing beam8 the second counter 20 is caused to emit a signal which is passed on tothe gate 16. This signal causes the gate 16 to close and thus stoppingthe passage of pulses from the detector input D (detector 11) to thefirst counter 17. Thus the counter 17 ceases to count the number ofpulses indicative of the revolution of the spinning turbine 2 withrespect to one meter of yarn withdrawn over the beam 8. The firstcounter has thus accumulated the number of revolutions of the turbine 2per 1 meter of the length of withdrawn yarn and thus provides a numberof twists imposed upon the yarn per l meter of the length. This may bedirectly represented or read out on the indicating unit l8 either as adigital number or in some other analog fashion.

If the decade number switch 19 had been placed at some other positionthen the pulses fed to the second counter 20 would be most applied by aconstant 10" where K is an integral number the value of which dependsupon the selection or adjustment of the decade number switch 8. As aresult the first counter 17 would accumulate the number of revolutionsof the spinning turbine per one meter of yarn multiplied by the constant10" The measurement time and thus also the accuracy of the result can beadjusted and varied by the use of this decade switch. In this connectionit is also necessary to insure that the number indicated on theindicating unit 18 would be in proper relationship and accordance withthe twist unit per number length, it is necessary to complete thenumeric value with a decimal symbol. That is the decimal point must beplaced in the read out number in a proper position between the digits onthe indicating unit 18 as given by the position of the decade numberswitch 8 to compensate for the use of the constant factor 10 to the Kpower.

The present invention may also be employed for measuring and indicatingthe imparting of a false twist to the spun yarn. In this instance thenumber of false twists may be given by the following relationship:

-Continued n l n Z V 17m. l

In which n represents the number of revolutions of the twist impartingmember of turbine per second.

V equals the withdrawing speed in meters per second. D the diameter ofthe twist imparting turbine in meters and the lambda equals thecoefficient of shortening or reduction of the sliver or ribbon.

By reducing the complex additivefactor to the constant value K thisrelationship may be easily determined with the system of the presentinvention. The value K. in conventional twist imparting turbines.commercially available, approximates plus 5. the sign plus applying tothe true or actual character of the yarn. This value varies so slightlybetween turbine units that it can be respected as a specific constant sothat first counter 17 may be set at an initial value of 0005 instead ofits initial zero value of 0000. By thus adding the value 5 to thecounter 17. the resultant indicated value takes into account theinfluence of the complex computation of the withdrawing speed. diameterand coefficient as given above for each 1 meter of yarn which iswithdrawn over the withdrawing beam 8 from the spinning turbine 2 duringthe measurement cycle. As a result the computation and indication of themeasurement is directed and straightforward as previously describedearlier.

lt is possible to modify the computation to provide a reading relativeto l centimeter of withdrawn yarn rather than through 1 meter ofwithdrawn yarn. To obtain a pulse reading from the detector 13 for each1 centimeter of yarn it is possible to provide a rotatable wheelengaging the surface of the withdrawing beam 8 which wheel contains theoptical indicia sensed by the detector as a ratio of the rotation of thewithdrawing beam 8. Such a system is shown in the aforementionedco-pending applications. In addition the number of revolutions of thewithdrawing beam 8 can be obtained by any other suitable means by whichthe motion is coupled with the motion of the withdrawing beam 8. Asimple brush and commutator device may be employed. Analogously thedetector 11 which senses the motion of the turbine 8 can be arranged andcoupled to the turbine 8 in any other manner than that described.

Should the spinning machine be provided with a mechanism by which thewithdrawing speed may be automatically changed and adjusted. the use ofthe repeated measurements made in accordance with the present inventionshowing the twist number per 1 meter of yarn length, can be employed tocontinuously make such adjustment. This can be obtained by providing thecounter 17 with preselection circuits. the outputs of which beingresponsive to the read out of the counter 17 so that the outputs may beused to regulate and control the operation of the withdrawing beam 8.Such preselection circuits may be employed for checking and maintainingthe accurate spinning of each of the spinning units in the spinningmachine.

It will be obvious from the foregoing that in accordance with thepresent invention the operation of each of the spinning units or theoperation and adjustment of the entire machine can be easily andautomatically checked. regulated and the twist factor determined. Theapparatus is simple and does not require a constant attendance by theoperator. The apparatus system may LII be manually controlled or it maybe automatically operated asdesired. The present invention may beapplied toany of the conventionally and commercially available machinerywithout extensive modification of such machinery. The location of thedetectors 11 and 13 are the only mechanical or structural devices thatneed be installed. These can be installed without modification of eitherthe turbine or the withdrawing beam 8. The operation requires only theselection of the measuring interval length that is whether the pulse isobtained are proportional to the meter of withdrawn spun yarn or to anamount greater or lesser than this. The indication of the resultdirectly in digital form on the digitronic discharge tubes of theindicating device considerably facilitates their recording. Thisindicating device may be visually read. may contain memory storage andrecording circuitry so that the read out can be maintained over periodsof time. It has been further found that the accuracy of measurements isquite high since the mechanical adjustment to produce optical markings12 on the spinning turbine per l unit meter length input upon withdrawalof 1 meter of yarn over the withdrawing beam 8 is approximately plus orminus one twist per meter and upon withdrawing 10 meters of yarn is plusor minus 0.1 twist per meter yarn length.

As defined herein a counter is a device or circuit which counts inputpulses. accumulates or stores the pulses and provides an output signaldirectly or proportionally indicative to the number of such pulsesreceived.

As used herein a decade switch may be defined as having two or moresections, each having ten times the value of the preceding section andeach section being divided into 10 equal parts. Each section has a 10position selector switch or its equivalent arrangement such that it maybe set at any given design value in its range.

As used herein gating means may be defined as a circuit or devicepermitting the selective passage of an input pulse or signal from oneunit to another and which is operable on the input of an independentsignal to it to either close or open said means to the passage of thefirst signals.

As used herein the indicator may be defined as a read out device foreither visual, digital or analog read out of accumulated pulses or pulsesignals and may include memory storage and recording means as well asoptical discharge tubes showing the read out value.

Various changes, modifications and embodiments have been suggested.Others will be apparent to those skilled in the art. Accordingly, it isintended that the present disclosure be taken as illustrative only andnot limiting of the scope of the invention.

What is claimed is:

l. A system for measuring and indicating the twist factor of spun yarnformed in an open end spinning unit having feed means for deliveringfibrous material. a rotary twisting means for spinning the fibers into ayarn. and a rotary withdrawing means for taking up the yarn comprising.first detector means located at said twist means for sensing therevolution of said twist means and providing an output having a valueproportional to the number of revolutions thereof a second detectingmeans located at said withdrawing means for sensing the revolution ofthe withdrawing means and providing an output having a valueproportional to the number of revolutions thereof. said first detectingmeans being connected to the input of a first counter, a gate means 0ndcounter includes a decade number switch.

3. The system according to claim 1 wherein said detectors arecontactless.

4. The system according to claim 3 wherein said detectors arephotoelectric cells and said withdrawing means and said twisting meansare provided with at least one optical marking.

1. A system for measuring and indicating the twist factor of spun yarnformed in an open end spinning unit having feed means for deliveringfibrous material, a rotary twisting means for spinning the fibers into ayarn, and a rotary withdrawing means for taking up the yarn comprising,first detector means located at said twist means for sensing therevolution of said twist means and providing an output having a valueproportional to the number of revolutions thereof a second detectingmeans located at said withdrawing means for sensing the revolution ofthe withdrawing means and providing an output having a valueproportional to the number of revolutions thereof, said first detectingmeans being connected to the input of a first counter, a gate meansinterposed between said first detector and said first counter, saidsecond detecting means being connected to the input of a second counter,the output of which is connected to the input of said gate, and whichprovides a signal for controlling said gate, and an indicator connectedto said first counter to record the value received by said counter.
 1. Asystem for measuring and indicating the twist factor of spun yarn formedin an open end spinning unit having feed means for delivering fibrousmaterial, a rotary twisting means for spinning the fibers into a yarn,and a rotary withdrawing means for taking up the yarn comprising, firstdetector means located at said twist means for sensing the revolution ofsaid twist means and providing an output having a value proportional tothe number of revolutions thereof a second detecting means located atsaid withdrawing means for sensing the revolution of the withdrawingmeans and providing an output having a value proportional to the numberof revolutions thereof, said first detecting means being connected tothe input of a first counter, a gate means interposed between said firstdetector and said first counter, said second detecting means beingconnected to the input of a second counter, the output of which isconnected to the input of said gate, and which provides a signal forcontrolling said gate, and an indicator connected to said first counterto record the value received by said counter.
 2. The system according toclaim 1 wherein said second counter includes a decade number switch. 3.The system according to claim 1 wherein said detectors are contactless.